<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN"
"http://www.w3.org/TR/html4/strict.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" lang="en">
	<head>
		<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
		<title></title>
		<script type="text/javascript">
			//取绝对值
			var res = Math.abs(-6);
			
			//四舍五入
			var res = Math.round(4.3);
			
			//向下取整
			var res = Math.floor(1.7);
			
			//向上取整
			var res = Math.ceil(1.1);
			document.write(res);
		</script>
	</head>
	<body>

	</body>
</html>
